I am convinced that resource depletion is likely to lead to social collapse - possibly within our lifetimes. Barring that, biological doomsday-weapon technology is becoming cheaper and will eventually be accessible to individuals. Unaugmented humans have proven themselves to be catastrophically stupid as a mass and continue in behaviors which logically lead to extinction. In the latter I include not only ecological mismanagement, but, for example, our continued failure to solve the protein folding problem, create countermeasures to nuclear weapons, and to create a universal weapon against virii. Not to mention our failure of the ultimate planetary IQ test - space colonization.